Hi Tom, just to give you something else to consider. I work all day on a computer as I suppose many do. But when I selected my system, yes I really wanted the 27" and the extra $ was not a problem. But I sat in front of it for a while at the store and just used it. Yes the screen is truly scrumptious! But I began to think of the amount of movement my eyes had to do to get the whole picture. It was just too much eye muscle work and for me I thought the 21.5 would be sufficient. I am glad I did. The 21.5 was the right choice for me. But you may be younger and eye strain / fatigue might not be an issue. They are both beautiful systems and the new iMacs are a real wow! Go Mac, you won't look back.